This CHA2DS2-VASc calculator scores stroke risk in atrial fibrillation from its seven clinical factors, and pairs the score with the published annual stroke rate and the usual anticoagulation threshold.
The Score That Decides Anticoagulation in AF
Its bleeding-risk mirror is our HAS-BLED Calculator — the pair is meant to be read together: CHA₂DS₂-VASc argues for treatment, HAS-BLED argues for caution and correctable risks, never simply against treatment. Part of our Health Calculators collection.
Worked Example
- 72-year-old with hypertension and diabetes: age 65–74 (1) + HTN (1) + DM (1) = score 3 → ≈ 3.2%/yr stroke rate — solidly in the anticoagulation-recommended band for either sex
- Female sex is a risk modifier, not a stand-alone indication: a 60-year-old woman with nothing else scores 1 (sex only) and is treated as low risk — the “Sc” point only counts when company arrives
- The two double-weight items (age ≥ 75, prior stroke/TIA) encode the data: previous embolism is the single strongest predictor of the next one
Score Discipline
- Non-valvular AF is the score’s home; mechanical valves and moderate-severe mitral stenosis live under different (warfarin) rules entirely.
- Annual rates vary by cohort and era; contemporary registries often read lower — the thresholds, not the decimals, drive decisions.
- Aspirin is not the fallback the 2000s promised: guidelines have largely retired it for stroke prevention in AF.
- Re-score with age and new diagnoses: the birthday from 74 to 75 alone adds a point and can flip the recommendation.
Related Tools
- HAS-BLED Calculator — major bleeding risk
- Target Heart Rate Calculator — cardiac fitness bands
- Health Calculators — the full collection
Frequently Asked Questions
How is the CHA2DS2-VASc score calculated?
One point each for heart failure, hypertension, diabetes, vascular disease, age 65–74 and female sex; two points each for age ≥ 75 and prior stroke/TIA/thromboembolism — maximum 9. This calculator sums them and reports the classic published annual stroke rate for the score (e.g., 3 → ≈ 3.2%/yr).
At what score is anticoagulation recommended?
Generally ≥2 in men and ≥3 in women (where the extra point is sex) — the zone where stroke risk clearly outweighs typical bleeding risk. A score of 1 in men (2 in women) is the “consider, individualized” band. This is educational framing, not a prescription.
Why does female sex score a point?
Registry data show women’s stroke risk in AF exceeds men’s mainly when other factors coexist; alone it doesn’t elevate risk. Hence the modern reading: sex is a modifier that counts only alongside at least one non-sex factor.
What stroke rates go with each score?
The classic Lip 2010 adjusted rates: 0 → 0%, 1 → 1.3%, 2 → 2.2%, 3 → 3.2%, 4 → 4.0%, 5 → 6.7%, 6 → 9.8%, 7 → 9.6%, 8 → 6.7%, 9 → 15.2% per year. Later cohorts differ somewhat; the table is reproduced as published, dip at 7–8 included.
Does a high HAS-BLED cancel a high CHA2DS2-VASc?
No — high bleeding risk prompts fixing what’s fixable (blood pressure, interacting drugs, alcohol, INR stability) and closer follow-up, not withholding anticoagulation from someone at high stroke risk. The two scores are a conversation pair, not opponents.
Is this CHA2DS2-VASc calculator medical advice?
No — it’s an educational calculator implementing a published score. Anticoagulation decisions require the full clinical picture and a treating clinician.